11817861 has 16 divisors (see below), whose sum is σ = 17306688. Its totient is φ = 7113600.

The previous prime is 11817859. The next prime is 11817863. The reversal of 11817861 is 16871811.

It is an interprime number because it is at equal distance from previous prime (11817859) and next prime (11817863).

It is not a de Polignac number, because 11817861 - 2¹ = 11817859 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11817863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4041 + ... + 6321.

It is an arithmetic number, because the mean of its divisors is an integer number (1081668).

Almost surely, 2^11817861 is an apocalyptic number.

11817861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11817861 is a deficient number, since it is larger than the sum of its proper divisors (5488827).

11817861 is a wasteful number, since it uses less digits than its factorization.

11817861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2452.

The product of its digits is 2688, while the sum is 33.

The square root of 11817861 is about 3437.7115934877. The cubic root of 11817861 is about 227.7786209148.

The spelling of 11817861 in words is "eleven million, eight hundred seventeen thousand, eight hundred sixty-one".